While I wouldn't quite describe myself as a hack day veteran, I've certainly attended a few in my time, mostly in the familiar confines of the Guardian's Kings Place HQ as we host both internal and external events for developers from all around the world. Last Saturday morning, however, found me wandering Moorgate, London, trying to find the Barbican Centre and grab some breakfast – all before 9am – so I could attend Music Hack Day London 2011.

The event, organised by Soundcloud's Dave Haynes and in its third year, featured hundreds of developers coming together to make something music related in 24 hours, then present it back to the group in a three-minute talk at the end of the weekend. Sounded straightforward enough, I thought, ascending the maze-like structure of the Barbican with my notepad of "hack ideas" in hand.

The day began with an intro talk by Dave and the event sponsors, and then we were given the opportunity to either leave the cinema room where talks took place and begin hacking, or stick around for a couple of hours' worth of technical presentations by sponsor companies such as Last.FM and Spotify. Unsurprisingly, most developers (myself included) chose to dive straight into the day. This was probably a little disheartening for the sponsors, whose audiences weren't large – perhaps next year the organisers might consider giving developers an hour or two to get their working environments set up and ready to go, and then begin presentations. It was only after hacking away for an hour that I realised I needed more information about the Spotify Apps API, for example.

The building itself was a great location – not that I'm not a fan of Kings Place, but the Barbican had three hacking rooms, one of which was the mysterious and exciting "hardware room". This area, normally a boardroom in its usual function, was filled with complex-looking circuit boards, glowing LEDs and XBox Kinects which some experimental hackers were playing with. Wandering around the building we saw art galleries and even an indoor greenhouse area with a fish pond and plants. This made for a nice change of scenery when the 2am code headache began.

By lunchtime we were properly into coding, with the sound of typing intermingling with odd curses and yells of joy depending on success rates. The relative quiet was occasionally broken with a splash of music from someone's laptop, usually glitching out and quickly muted, and one corner of Hacking Room 1 kept echoing the sound of Darth Vader's now-infamous "nooooooooo!" clip as, presumably, someone's hack stopped working.

I chatted to a couple of developers sitting opposite me, who quickly became my surrogate advisors as I pondered aloud about specifics of one of my hacks as the clock approached midnight. "What's the most pretentious colour?" was one issue they solved for me, after I lent them a hand with their javascript. Similarly, I swapped Spotify app tips and frustrations with a guy sitting alongside me, and quizzed the Spotify team over IRC as we hacked. The atmosphere was one of playfulness and discovery; while we were all competing, perhaps indirectly, there was certainly a desire just to see what people were up to, and an aura of energy as people felt inspired and impressed by what others were doing.

Energy was beginning to flag as the clock approached midnight, but organiser Dave was on hand to administer cans of Red Bull to keep everyone pumped. When 2am rolled around I was still coding, but decided to head for home. While it's quite common for hack day attendees to camp out overnight at their venues, we'd been told that when the Barbican's security guards left at 2am, we wouldn't be able to get in or out of the building till the following morning. I didn't much fancy a lock-in, so left just before the doors were closed for the night. A frustratingly slow night bus later and I was home, exhausted but satisfied with my day's hacking.

The following morning I was up and once more making my way to the Barbican, even more bleary-eyed than the day before. There was only time for a couple of hours' hacking before presentations began, so it was mostly a case of polishing my two apps for the demo. In the final hours of Saturday I'd thrown together the Pretentiometer, an app that compares the user's music taste with the top-rated albums on hipster music webzine Pitchfork. Along with Chordify, my Spotify/guitar mashup, I was ready to present.

In the end there were more than 60 hacks to present, with three minutes each to demo their work. This must have been a logistical nightmare, so kudos to Dave and his team for managing to finish slightly ahead of the three hour schedule. Heartbreakingly, some of the demos failed to work. Most of the hardware hacks had difficulties on the stage, having to fall back to pre-recorded videos, and one poor guy's laptop refused to connect to the projector and he had to return with a borrowed machine later on.

My own presentation went quite well, after some initial worries that my laptop would refuse to work with the projector screen too. My comrades from the evening were less lucky, though – their ambitious Soundcloud Mixer, an app which allowed users to mix recordings together live in a web browser, didn't quite work at demo time, which saw them scrabbling around onstage trying to make their midi sequencer work. On the other hand, when Ian Butterworth's awe-inspiring CloudChamber hack didn't quite work, he went with his backup plan – playing a Phil Collins song live through the Reverb Chamber at the National Physical Laboratory.

One concern of mine about the event was gender balance. I wrote earlier this year after seeing Dave present a talk at SXSW in Austin, Texas, about the lack of female presence at events like hack days. I wasn't sure what to expect for this weekend, but I'd estimate from the two days that the male:female ratio was probably somewhere around 10:1. I didn't know back at SXSW what the solution was to this, and I still don't now – I know it's not the fault of the organisers or attendees, so perhaps this whole issue is an outcome of the UK government's outdated policy on IT education in schools. Either way, it would have been nice to see a more representative gender balance at the event.

One other criticism was of how we developers went about the event. Hack days involve hours of coding, often into the night, all for the comparatively tiny period of two or three minutes onstage to explain your work. Some of the presenters wasted their first few minutes giving a jargon-laden introduction to the technologies they'd used and problems they faced, then said, "now for the demo". In my opinion, the entire presentation should be the demo. The hack day itself is the time for self-indulgent geekery, but the presentation should be condensed and simplified: this is my use case, this what it does.

Thinking about all of this, I felt torn: a hack day should be a place where people can just build whatever they like, scratch an annoying itch, solve a personal problem. Not every hack should have a commercial application or a million-strong userbase. But I also think that the output of these things should be understandable and appreciable to everyone, regardless of their technical background. That said, it's nice that geeks like myself can have a space where they can experiment and nerd out with fellow hackers, outside of their day jobs where they probably do have to bow to corporate pressure and business considerations.

For me, the standout thing about the event was the organisation: the rooms were well set-up and technically equipped. Food was good, timely and in decent quantities, and organisers were friendly and helpful whenever needed. Massive thanks and respect to Dave and his team, and to the fellow developers hacking along with me over the weekend. I'll be there again next year.